Problem: Simplify the expression. $(-4r^{4}+r^{3}+r)(5r^{3})$
Answer: First use the distributive property. $ - 4 r^4 (5 r^3) + r^3 (5 r^3) + r (5 r^3) $ Simplify. $-20r^{7}+5r^{6}+5r^{4}$